Don't pipe PanicAlerts to netplay window if it isn't opened

This is something that was quite confusing for me while trying to get
netplay to work for me; once the Connect/Host buttons were pressed,
the UI would hang, only to work again a few seconds later, but with
no error message or explanation *at all*.

Turns out this is because panic alerts are shown in the netplay window
instead during netplay, even before it is even shown.

This fixes it by "piping" the alerts to the netplay chat only if the
netplay window is visible.

(regression introduced in #3823)

0 files changed, 0 insertions, 0 deletions